Cisco Security Advisory – A vulnerability exists in the Cisco Network Admission Control (NAC) Appliance that can allow an attacker to obtain the shared secret that is used between the Cisco Clean Access Server (CAS) and the Cisco Clean Access Manager (CAM).
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/65584/cisco-sa-20080416-nac.txt
Source: https://packetstormsecurity.com/files/65584/Cisco-Security-Advisory-20080416-nac.html